I did that earlier today -- creating a new Google account, adding that as a Family account to my YTTV subscription, and then trying to authenticate YTTV TVE in Channels with the new Google account linked to YTTV.
It still did NOT work for me, using a VPN connection. Now, unlike before when I was just trying with my original YTTV ID, when I tried with the new ID, I get a similar failure to authenticate message, but this one is now the "Captcha" error variety one. Tried it several different ways, all with the same failure result.
Just to be clear, I have absolutely no problem directly signing into and using my YTTV account either on the PC that hosts my Channels DVR server or on various streaming devices. It's only the Channels DVR TVE authentication via YTTV that's failing.